Polychrome screen and process of making the same.



of Austria-Hungar E nares rnrniur omen mmonr h. m m) ALADAR SCHULLER, or cons-son, NEAR anrwnnr, BELGIUM.

' POLYGHROME SGREEN AND PROCESS OF MAKING THE SAME.

To all whom it may concern:

Be it known that we, RUDoLr RUTH, a citizen of the United States of America, and ALADAR Sun a subject of the Emperor both residing at Oude- God, 'n'ear Antwerp, Belgium, have invented certain new and Y useful Improvements in Polychrome Screens and Processes of Makthe Same;and we do hereby declare the in "fofiowing to be a full, clear, and exactde scription of the invention, such as will enable othersskilled in the art to which it appertains to make andnse the same. Our invention relates to polychrome screens fpr' color photography.

For making photographic pictures in nat- I ural colors b the trichromatic process three layers dyed 1n the three primary colors are necessary which are used at first as receiving filters, either as complete layers or in the form of screens, and afterward for producing the colored picture.

In color screens such as arenow in use the receiving-filters or color screen elements are used for roducing the colored picture.- But when ma 'ng therefrom colored paper, pictures it is absolutely necessary, that the colcred elements which produce the pictures have a considerably lighter tint and are much more translucent than before when serving as receiving filters;

By means of the color screens which have heretofore been in use a good paper picture can not be produced, because the filter ele; ments must be so strongly dyed, and are therefore so deeply colored that they can not be used thereafter 'as' elements for producing the picture.

The object of the improvements is to'avoid this objection. And with this object in View our invention consists in providing a color screen which has a lighter tint when producing the picture than before, when it acted as a filter. As a foundation :1 screen plate is used which is made for example fromsuitable screen materials as fromcolloidal substances such as gelatin. A solution of gelatin is 'dyed with two dye stuffs of the same color (not-necessarily of the same depth of color) but difierent properties and atomized in a suitably, heated chamber; by choosing an appropriate height of fall the size of the resultant colored particles may be deter-' Specification of Letters Ifatent.

afterward easily done for example by washing the same out,

- following completely been removed.

Thereby two kinds of dyestuffs are applied to each color screen, one of which 13 fixed or can be fixed in the colloid forming the foundation, while the other one can be removed. This may be colors.

in which case dyestufis of acid and basic character are used, for the reason that, as is known in the art, the acid dyestuii can not be removed from the gelatin by washing, -while the dyestufis.

of basic character canbe washed out. The color screen has thus been prepared is used in the way after first applying a sensitive emulsion: The color screen is exposed to the light from the rear and through the filtering elements and developed in way. After fixing and washing a sheet of paper is pressed thereon and the whole layer easil wine is drawn oil, so that the filtering elements are brought to the top. In case of colloids which are soluble in water, such as gelatin or starch, the layer is drawn 01% according to methods known in photomechanics. For example, the plate is' brought into a diluted solution of hydrofluoric acid (1%), where by gas globules of silicon tetrafluorid are formed on the glass which permit the layer to float ofi' (see Eder, Rezcpt 11-. Tab., page 30). Or the glass plates are coated with an exceedingly thin layer of caontchouc and collodion. When using resin as screen layers the glass plates are treated with talcum. After the picture has been drawn oil it is washed until the non-fixed .dvestufi's have Patented Mar, 24, 1914. Application-filed October 8, 1912. Serial No. 724,578.

the usual As an example,'the following dyestuffs I will be given, which are suitable for colloids containing water, such for example as starch: For each screen we use one mordant dyestufi, such for example as fuchsin. malachite green, patent blue, otherwise known as the disulfonic acid of the condensation product from metaoxybenzaldehyde, and one acid dyestufl, suchfor example as oxamin red, oxamin green, and oxamin blue. The mordant dyestufls are fixed by potassiumantimonyltartrate and tannin, while the acid dyestuffs remain soluble and can be washed out. When carrying this method out for each screen grams of starch are dyed, in one case with fuchsin 5 grams, oxamin red 5 grams, in the second case with malachite green 5 grams, oxamin green -5 grams, and inthe of triphenyl-p-rosenalin and triphenyl rosenalin (see'Dammer Uiwm'iscke Teohvwlogic der Neuzez't 1911, Vol. 'II page 980). The following example gives good results: For each plate 100 grams of mastix resin are dyed in one case with Sudan III agfa 5 grams, fuchsin H'cichst 5 grams, in the sec.- ond 'case with moti-yellow VVeiler ter mer 5 grams, naphthalene yellow Casella 5 grams,

in the third case with moti-blue Weiler t. m. 5

grams, spirit-blue Casella 5 grams. From these three masses of resin which have been v dyed with different dyestufis a single screen is made in the usual way which after the picture has been completed are treated with benzin, so that the soluble dyestulf is removed. Furthermore we may use dyestuiis which are adapted to be bleached by light together with such dyestuffs which are not bleached} For example Fulpid dyestuffs may be used which have been described in Eder, J ahrbuc/i 1910, page 161. The screens are afterward exposed to the light, so that one of the dyestuffs is bleached out. As the time which 15 required for affecting the si1- var bromid element is short as compared to the time which is'necessary for changing the Fulpid dyestuffs, thelatter are not de-' composed while the picture is being taken.-

The following is'an example of the use of Fulpid dyestuffs with. colloids containing wateri In each case 1.00 grams ofcolloid are dyed in one case with fuchsin 'Hiichst 5 grams, Fulpid red 5 grams, in the second case with auramin Hiichst 5 grams, Fulpid yellow 5 grams, in thcthird case with Victoria blue Hiichst 5 grams, dicyanin Hochst 5 grams. 1

Each screen is-made in the manner described above and then sensitized, and it is exposed after development to the free sun light about on minute, orto the diffused day lighter electric are light, 'etc., about 1.0

or 15 minutes. Thereby the Fulpid dyestuds and dicyanin are bleached out, while the other dyestuffs are not altered.

An example. for resin screens is the following: In each case 100 grams of'colophony are dyed in one case-with Sudan I-V agfa 5 grams, Fulpid red 5 grams; in the second case with naphthalene yellow 5 grams, Fulpid yellow 5 grams, in the third casewith spirit blue Casella 5 grams, dicyanin Hochstb grams, a

In the part of the invention claimed, which invention comprises only the screen prepared with its two kinds of dyestuffs one fixed and the other removable, in the threeprim'ary colors.

We claim herein as our invention:

1. In the process of making a polychrome screen the step which comprises treating a suitable screen material with two coloring materials of the same tint, the tint of one of said materials bein fixed and ofthe other removable, and app ying said colored screen material toa suitable light penetrative support.

2. In the proces of making a polychrome screen the step which comprises treating a colloid screen material with two coloring materials of the same tint, the tint of one of said materials being fixed and. of the other removable, and applying said colored screen material to a suitable light penetrative sup port. r

' 3. In the process of making, a polychrome screen the step which comprises treating gelatin screen material with two coloring materials of the same tint, the tint of one of saidmaterials being fixed and of the other removable, and applying said colored gelatin to a suitable light penetrative support.

i. A polychrome screen comprising a suitable light penetrative support and 'a layer of screen material upon said support said material being colored with two different coloring materials of the same tint in each of the three primary colors the tint due to one of said materials being fixed and that due to the other of said materials being removable.

In testimony whereof we hereunto aiiix' our signatures inthe presence of two witnesses.

- RUDOLF RUTH. I

ALADAR SCHULLER.

Witnesses:

E. Jaoon's,

N. ADAMS..

resent ease the picture forms no 

